The early detection of disease increases the chance for successful therapeutic intervention. Non-invasive optical diagnostic devices which detect changes in the biochemical and structural features of tissues provide tools to detect the early stages of disease (e.g., cancer). An optical device for detecting tissue features typically comprises a console unit which includes a light source, a detector, electronics, and a computer, in communication with an optical probe through which light is transmitted to and from a tissue. The optical probe can be the end of a fiber optic cable or can contain complex optical elements intended to shape an output light beam from an optical source into a desired geometry.
Optical probes coupled to endoscopic devices have been used to obtain tissue-specific information from patients. Representative organs which can be characterized using an endoscopic approach include the colon, uterus, bladder, and stomach. Fluorescence spectroscopy using endoscopic optical probes can distinguish between cancerous and precancerous tissue in these organs. However, the development of optical probes for clinical use has been hampered due to the difficulty of miniaturizing the optical elements necessary for the collection of optical data. Additional constraints arise because an optical probe, like any medical access device, must be decontaminated and sterilized prior to reuse. The delicate construction of light directing and focussing elements within the optical probe generally make it difficult, if not impossible, to sterilize the probe.
Because it is generally not economical to discard an optical probe after a single use, it is desirable to provide an accessory device which acts as a shield between the illumination optics of the optical probe and the tissue being analyzed. While it is generally known in the art to equip a medical device with a protective barrier or sheath to provide a cover for the device, it is desirable to provide an accessory device for an optical probe which serves more than a mere barrier function, but which complements the function of the optical probe. Accordingly, the present invention provides an accessory device for an optical probe which comprises multiple optional features to enhance the versatility of the device in in vivo diagnostic procedures.